Hermetic compressor assembly



May 10, 1966 s. A. PARKER HERMETIC COMPRESSOR ASSEMBLY 2 Sheets-Sheet 1 Filed Sept. 8, 1964 May 10, 1966 s, PARKER 3,250,461

HERMETIC COMPRESSOR ASSEMBLY Filed Sept. 8, 1964 2 Sheets-Sheet z United States Patent 3,250,461 HERMETIC COMPRESSOR ASSEMBLY Sidney A. Parker, Fort Worth, Tex., assignor to Lennox Industries Inc., a corporation of Iowa Filed Sept. 8, 1964, Ser. No. 395,001 6 Claims. (Cl. 230-232) This invention relates to a welded shell-type hermetic refrigerant compressor wherein the motor is connected to a vertically-disposed drive shaft which is operatively connected to a plurality of pistons disposed in cylinders located beneath the motor and, more paricularly, to improved integral suction muflling means and resilient supporting means for mounting the compression mechanism manifold and cooperating with the compressor block to define a discharge muflling chamber.

Air conditioning and refrigeration systems are now regarded as being necessities in many commercial and domestic applications. With the broader acceptance and use of such systems, many design restrictions have been placed on the equipment. Among the primary considerations with respect to the compressors commonly utilized in such systems, is that the compressor is dependable, inexpensive to fabricate and quiet in operation. Contributing to relatively noisy compressor operation have been deficiencies in the suction muffling construction and the mounting of the compressor block within the compressor housing.

An important object of the present invention is to provide a hermetic reciprocating compressor having an improved suction gas muffling means arranged internally thereof, such suction muffling means being defined partially by ring means which forms an annular mufiling space within the compressor housing.

A further object of the present invention is to provide a hermetic compressor having improved resilient mounting means therein, such resilient spring means acting between cooperating flange means which define a suction gas mufl'ling chamber.

Yet another object of the present invention is to provide a hermetic compressor having a heat shield disposed about the shell which envelops the compressor block for (1) insulating the relatively hot discharge gas in the discharge muflling chamber from the relatively cold suction gases entering the compressor to minimize increase in suction gas temperature and thereby minimize undesirable loss in compressor capacity and (2) dampening the-sound energy radiating from the shell.

Still another object of this invention is to provide a hermetic refrigerant compressor of the welded shell type with improved suction gas mufiiing means comprising first, second and third chambers defined within the compressor by ring-like members disposed intermediate the top and bottom of the compressor, such ring-like members carrying spring members for resiliently supporting the compression mechanism within the outer housing of the compressor.

Further objects of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which like numerals refer to like parts, and in which:

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FIGURE 1 is a vertical cross-sectional view of a hermetic refrigerant compressor embodying the present invention;

FIGURE 2 is a cross-sectional view of the hermetic refrigerant compressor taken generally along the line 22 of FIGURE 1; and

FIGURE 3 is a detail sectional view taken generally along the line 33 and illustrating the manner of afiixing the heat shield in position on the compressor block.

Referring to FIGURE 1, there is illustrated a compressor 10 embodying the present invention. The com pressor comprises a gas-tight housing including an upper shell 12 and a lower shell 13 integrally joined to one another, as for example, by welding. To the bottom of the exterior surface of the lower shell 13 are Welded a plurality of legs 14, by means of which legs the compressor may be supported in upright position within a condensing unit or an air conditioning unit.

Supported within the outer housing or casing of the compressor 10 is a compressor block'16 which comprises a motor flange portion 17 and a cylinder crankcase portion 18 divided by a partition 19. An annular sleeve 20 surrounds the lower portion 18 of the crankcase and cooperates with the exterior of the compressor block 16 to define a discharge gas muffling chamber therebetween, as will be more fully described hereafter.

Formed integrally on the top of annular sleeve 20 is an outturned ring-like flange 22. An annular mounting ring 24 having a transversely disposed lower ring-like flange 25 is afiixed to the lower shell 13 of the housing. The flanges 22 and 25 are disposed in spaced relationship to one another.

A plurality of resilient spring means are provided between the flanges 22 and 25 for resiliently supporting the crankcase within the outer housing. Each spring means comprises an elongated rod .or stem 26 which extends through openings in the flanges 22 and 25, respectively. Seated in an opening in the flange 22 is a bearing member 28 which slidably journals the stem 26.- Disposed be- 4 tween the flanges 22 and 25 is a spring 30 for biasing the shell 20 and the compression mechanism housed therein upwardly with respect to the outer housing. Concentri cally disposed about the upper end of the stem 26 is a sleeve-like member 32 which carries concentrically thereabout a spring 34 for biasing the compressor block and the compression mechanism therein downwardly with respect to the outer housing. The sleeve 32, which seats at one end on wear washer 27, is held in place by retain ing means which include washer 35 and nut 36 atfixed to the end of the stem 26. The washer 27 prevents the spring 34 from wearing upon the plastic washer 28 and changing the predetermined setting of the spring means.

As best seen in FIGURE 2, in one presently preferred form of theinvention, four resilient spring means are equidistantly spaced about the interior of the compressor. In use, the crankcase is resiliently supported in the outer housing in an etfective manner. Furthermore, during shipment up and down as well as side to side movement of the crankcase relative to the outer housing is restricted within safe limits by the organization of the spring means, by the close association between the exterior of sleeve 20 and mounting ring 24, and by the close proximity of the end cap and bottom of the annular sleeve 20 with respect to the outer housing.

Turning again to a consideration of the crankcase 16, it is seen that there are provided in the crankcase a pinrality of separate cylinders 38. Though a four-cylinder compressor is illustrated, it will be understood that any ably mounted therein a wrist pin 42 upon which there is journaled one end of a connecting rod 44. The other end of each connecting rod 44 is aflixed to the eccentric portion 45 of the crankshaft 46.

Provided in the end of each cylinder 38' and closing the end of the cylinder cavity are valve assemblies 48. Such valve assemblies 48 may comprise a discharge valve unit 49, a suction valve plate 50', a suction valve or reed member 51. Each valve assembly is operative in a conventional manner as will be set forth more fully hereafter.

Each of the valve assemblies 48 is held in place in the end of a cylinder by means of an end cap 52. End cap 52 is maintained in place by means of a spring member 54 and a retaining ring 56. It will be noted that an O-ring 58 is provided in an annular recess in the side wall of end cap 52 for sealing the discharge side of the end cap from the suction side of the end cap or cylinder head.

Provided on the compressor body 16 are a pair of annular circular sealing flanges 60 and 62. These flanges are provided with recesses within which are disposed O-rings 64 and 66 for sealing between the annular sleeve 20 and the flanges 60 and 62, respectively, on compressor block 16. Defined between the compressor block and the annular shell or sleeve 20 is a space or cavity 68 into which discharge gases are passed from the cylinders 38 after compression. The discharge gases pass through a plurality of mufiling cavities in the chamber 68 through a discharge connector assembly 68' (FIGURE 2) to the conduit 69 for discharge from the compressor to the condenser of the refrigerating system in a known manner.

'The drive shaft 46 is preferably of the type best shown and illustrated in copending application, Serial No. 361,- 126, filed by Sidney A. Parker. The drive shaft or crankshaft 46 is journaled within a lower bearing 70 which is mounted in the lower bearing head 71. The lower bearing head is maintained in position by a suitable wedge lock spring or retaining ring 72 which seats within an annular groove in the compression block. Also provided in the lower bearing head 71 is a thrust bearing 73 which has a central opening 74 defined therein. Located in the lower portion 75 of the crankshaft 46 adjacent the counter- Weight portion 77 of shaft 46 is a coaxially disposed hole which constitutes the eye of the impeller means which are defined within the crankshaft 46.

Briefly, there are provided within the crankshaft 46 three separate pump means-a pump 80 for lubricating the upper bearing surfaces defined between crankshaft 46 and upper bearings 81 and 82, a pump 83 for providing a high-pressure supply of lubricant from the sump 84 defined within the outer casing at the bottom thereof to the connecting rod bearing surfaces, and a third pump 7 (not shown) for providing a low-pressure supply of lubricant from the sump 84 to the connecting rod bearing surfaces. 7

A vent passage 85 may be provided in the upper end of crankshaft 46 for overcoming the tendency of refrigerant vapor or film to prevent proper lubrication of the upper bearing surfaces. Passage 85 communicates the upper end of passage 80 with an annular space 86 defined be- 4 20 for preventing heat transfer from the relatively hot discharge gas inthe discharge muflling chamber to the relatively cold suction gas entering the compressor. An undersired increase in suction gas temperature will, by virtue of the compression process, result in increased discharge gas temperature at the cylinders. Such increased discharge gas temperature results in accelerated oil breakdown, increases adverse chemical reactions, and enhances undesired copper plating of the valves. ing suction gas temperature will increase the operating temperature and reduce the efficiency of the motor and motor life. The suction gas temperature increase will cause the suction gas to become less dense, resulting in lowering of pumping capacity.

The annular sleeve or shield 92 is provided with a pair of continuous annular depressions 93 and 94 for suitably spacing substantially the entire shield 92 from the exterior of the annular sleeve 20 and for insulating the intermediate portion of sleeve 20 between the two depressions from the suction gas.

As best seen in FIGURES 2 and 3, the heat shield 92 is aifixed to the flange 22 at the top of the annular sleeve 20 by means of angle-shaped tabs 96 and 98. The heat shield 92 effectively insulates the cold suction gas entering the compressor from the relatively hot dis-- charge gas in the discharge gas muffiing chamber.

The suction gas in the compartment 91 flows through annular opening 101 and through inlet openings 102 in flange 25 into an annular space or compartment 100 defined between the flanges 22 and 25 of the annular sleeve 20 and the mounting ring 24, respectively. It is to be noted that the narrow annular restricted opening 101 is defined between the end of the flange 25 and the heat shield 92. The end of the flange 22 is spaced from the mounting ring 24 so as to provide an annular restricted opening 104. In addition, openings 103 are provided in flange 22 (FIGURE 2). The openings 103 and the annular opening 104 define outlet means from the suction muffling chamber 100 to the upper compartment 106 defined between the outer housing and the top portion of the compressor mechanism. From compartment 106, the suction gas flows through the opening 107 in the end cap 108 into the motor compartment, and over the electric motor 109, thereby cooling the motor. The suction gas then passes from the motor compartment into the valve assemblies, 48 via suction openings 110 provided in the compressor block.

The motor 109 comprises a stator 111 which is mounted within the motor flange portion 17 of the compressor block or crankcase 16. The stator 111 is inductively connected to the rotor 112 which is affixed onto the upper portion of the crankshaft 46. The rotor 1 12 may be connected to the crankshaft or drive shaft 46 by means tween the crankshaft and the upper portion of the compressor block. Provided beneath the bearing 82 in the wall of the compressor block is a groove or skived out area 88 for communicating space 86 with the interior of the compressor. As is known in the art, a second vent passage may be formed in crankshaft 46.

Suction gas enters the outer housing of the compressor via suction line 90. The incoming suction gas flows into the large annular compartment 91 defined between the annular shell and the outer casing below flange 25. Heretofore, the relatively cool suction gas has passed in heat exchange relationship with the annular sleeve 20, causing an undesired increase in suction gas temperature.

It is a feature of the present invention that a heat shield 92 be provided concentrically about the annular sleeve of a key 113 held in position during operation by suitable retaining means. onto shaft 46.

Affixed to the flange 60 of compressor block 16 and depending into the discharge muffling chamber 68 is a device 124 for detecting the compressor discharge gas temperature and for terminating operation of the compressor motor 109 upon attainment of a predetermined discharge gas temperature.

A plurality of terminals 114, 115,116 and 117 are provided on the top of the upper housing portion 12 in order to conduct electrical current from a suitable source to the motor and provide for connection of suitable motor protection while preserving the hermetic nature of the compressor.

To further reduce the possibility of noise being created by vibration of the outer housing of the compressor, annular rings 1 18 and 1 20 are disposed within the outer housing in intimate frictional engagementwith shell members Hand 13, respectively.

By the present invention, there has been provided an effective internal suction mutfiing arrangement which is Further, increas- If desired, the rotor may be shrunk formed from integral components of the compressor. The novel suction mufliing arrangement is one important factor contributing to a very low noise level for the present compressor. The annular rings which are part of the suction mufiiing means also form the support mem bers for the resilient means which support the crankcase within the outer casing in a substantially sound-isolated and vibration-free manner. These novel structural features coact to produce a hermetic reciprocating compressor which is very quiet in operation. Further, there has been provided a novel heat shield for minimizing heat transfer between the hot discharge gas and the relatively cool suction gas, thereby preventing undersirable increase in suction gas temperature and increasing compresor performance.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new, and desire to secure by Letters Patent of the United States, is:

1. In a reciprocating compressor, the combination of an outer casing, an annular sleeve within and spaced from said outer casing for forming an annular space therebetween, a compressor block carried in said annular sleeve and defining a crankcase therein, a vertically extending crankshaft jonrnaled in said block, said block defining at least one cylinder, a piston reciprocatingly disposed in said cylinder, means operatively connecting said piston to said crankshaft, an electric drive motor carried by the block and being operatively connected to said crankshaft, means defining a first annular flange formed on said sleeve, an annular mounting ring secured to said outer casing and having a second annular flange thereon extending toward the annular sleeve and being spaced therefrom to form a narrow annular opening, said first annular flange being spaced from said mounting ring to define a second narrow annular opening, resilient spring means mounted between said first and second flanges for floatingly mounting said compressor block with respect to said outer casing, said flanges being vertically spaced from one another so as to define a suction mufliing chamber therebetween, there being a relatively large chamber defined below said second flange and a relatively large chamber defined above said first flange, a suction gas inlet aflixed to said outer casing below said second flange, whereby suction gases enter the lowermost relatively large chamber defined below said second flange, flow through the first narrow annular opening into said intermediate suction mufiling chamber, and then through said second annular opening from said intermediate mufiiing chamber into said relatively large uppermost chamber, thereby effectively mufliing the incoming suction gases.

2. In a reciprocating compressor of the type comprising an outer sealed casing, an annular sleeve within and spaced from said outer casing and forming an annular space therebetween, a compressor block carried in said annular sleeve, a vertically extending drive shaft journaled in said compressor block, compression mechanism in said compressor block operatively connected to said drive shaft, drive means for actuating said drive shaft, there being a discharge gas chamber formed between said compressor block and said annular sleeve, discharge line means communicating said discharge gas chamber with a discharge line exterior of said compressor, and suction line means connected to said outer casing for returning refrigerant to said compressor, the improvement comprising means defining a first annular flange on said annular sleeve, a mounting ring fixed to said outer casing and having a second annular flange projecting therefrom in spaced relationship to said first flange, spring means dis posed between saidfirst and second flanges for resiliently supporting said compressor block within said outer casing, there being a first compartment of relatively large size formed between said second flange, annular sleeve and the interior of said outer casing, a second compartment of relatively small size formed between said first and second flanges, and a third compartment of relatively large size formed between said first flange, said compressor block and the interior of said outer casing, means defining a first restricted opening for communicating the first compartment and the second compartment, and means defining a second restricted opening for communicating the second compartment and the third compartment, and suction line means communicating with said first compart ment, whereby suction gas enters said first compartment and flows to said compression mechanism through said second and third compartments respectively, thereby ef fcctively muffling the suction gas.

3. In a reciprocating compressor, the combination of an outer casing, an annular sleeve within and spaced from said outer casing for forming an annular space therebetween, a compressor block carried in said annular sleeve and defining a crankcase therein, a vertically extending drive shaft journaled in said block, said block defining at least one cylinder, a piston reciprocatingly disposed in said cylinder, means operatively connecting said piston to said drive shaft, an electric drive motor carried by the block and being operatively connected to said drive shaft, a first anular flange formed on said sleeve, means defining a second annular flange formed on a mounting ring secured to said outer casing, said flanges being spaced from one another to define a relatively large suction muffling chamber below said second flange, an intermediate suction mufiiing chamber, between said flanges, and a relatively large suction mufliing chamber above said first flange, there being restricted inlet means to said intermediate mufiling chamber and restricted outlet means from said intermediate muflling chamber, a suction gas inlet aifixed to said housing below said second flange and communicating with said large mutfling chamber below said second flange, and resilient spring means mounted between said first and second flanges for resiliently 'supporting said compressor block within said outer casing, whereby suction gases enter the compressor below the second flange and pass from the relatively large chamber below said second flange through the restricted inlet means into said intermediate mufliing chamber, and then pass from said intermediate muffling chamber through said restricted exit means into said relatively large chamber above said first flange, thereby effectively muflling the incoming suction gases which then pass over the electric drive motor for cooling the same.

4. A reciprocating compressor as in claim 3, wherein said resilient spring means comprises an elongated stem member passing through openings provided in said first and second flanges, and spring means concentrically disposed on said stem member, comprising a first spring disposed between said flanges to bias said flanges from one another and a second spring disposed between one flange and an end of said stern member for biasing the crankcase and compressor block downwardly in said outer casing.

5. In a reciprocating compressor of the type including a compressor block, a drive shaft journaled in said block, said block defining at least one radially disposed cylinder, a piston reciprocatingly mounted in said cylinder, said piston being operatively connected to said drive shaft, a first annular sleeve surrounding said block in sealing engagement therewith to define an annular discharge gas cavity between said sleeve and said block, a valve assembly closing the end of said cylinder, means retaining the valve assembly in said cylinder, and a suction gas inlet affixed to the lower portion of the outer casing of said reciprocating compressor for permitting the suction gas to enter said compressor, the improvement comprising a second annular metallic sleeve concentrically arranged 7 about said first annular sleeve and disposed between said first sleeve and the outer casing for insulating the incoming suction gas from the relatively hot discharge gas so as to reduce both dischargeand suction gas temperatures, thereby improving compressor performance.

6. In a reciprocating compressor of the'type including a sealed outer casing, a compressor block in said casing, a drive shaft journaled in said block, said block defining at least one radially disposed cylinder, a piston reciprocatingly mounted in said cylinder, said piston being operatively connected to said drive shaft, a first annular sleeve surrounding said block in sealing engagement therewith to define an annular discharge gas cavity between said sleeve and said block, a valve assembly closing the end of said cylinder, means retaining the valve assembly in said cylinder, and a suction gas inlet aflixed to the lower portion of the outer casing of said reciprocating compressor for permitting the suction gas to return to said compressor, and wherein the suction gases pass in heat transfer relationship With the annular shell member and is undesirably heated, thereby reducing the efficiency of the compressor, the improvement comprising a second annular metallic sleeve in said casing arranged about said first annular sleeve and disposed between said firs-t annular isleeve and the outer casing for insulating the incoming suction gas from the relatively hot discharge gas so as to minimize temperature increase of the suction gas prior to entry into said cylinder, thereby improving compressor performance.

MARK NEWMAN, Primary Examiner. 

1. IN A RECIPROCATING COMPRESSOR, THE COMBINATION OF AN OUTER CASING, AN ANNULAR SLEEVE WITHIN AND SPACED FROM SAID OUTER CASING FOR FORMING AN ANNULAR SPACE THEREBETWEEN, A COMPRESSOR BLOCK CARRIED IN SAID ANNULAR SLEEVE AND DEFINING A CRANKCASE THEREIN, A VERTICALLY EXTENDING CRANKSHAFT JOURNALED IN SAID BLOCK, SAID BLOCK DEFINING AT LEAST ONE CYLINDER, A PISTON RECIPROCATINGLY DISPOSED IN SAID CYLINDER, MEANS OPERATIVELY CONNECTING SAID PISTON TO SAID CRANKSHAFT, AN ELECTRIC DRIVE MOTOR CARRIED BY THE BLOCK AND BEING OPERATIVELY CONNECTED TO SAID CRANKSHAFT, MEANS DEFINING A FIRST ANNULAR FLANGE FORMED ON SAID SLEEVE, AN ANNULAR MOUNTING RING SECURED TO SAID OUTER CASING AND HAVING A SECOND ANNULAR FLANGE THEREON EXTENDING TOWARD THE ANNULAR SLEEVE AND BEING SPACED THEREFROM TO FORM A NARROW ANNULAR OPENING, SAID FIRST ANNULAR FLANGE BEING SPACED FROM SAID MOUNTING RING TO DEFINE A SECOND NARROW ANNULAR OPENING, RESILIENT SPRING MEANS MOUNTED 